diff --git a/lib/render.py b/lib/render.py
index 63ad935..b760672 100644
--- a/lib/render.py
+++ b/lib/render.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python2
 # -*- coding: UTF-8 -*-
 # File: render.py
-# Date: Sun Jan 11 23:43:03 2015 +0800
+# Date: Sun Jan 11 23:46:06 2015 +0800
 # Author: Yuxin Wu <ppwwyyxxc@gmail.com>
 
 import os
@@ -154,6 +154,7 @@ class HTMLRender(object):
 
     def _render_partial_msgs(self, msgs):
         """ return single html"""
+        self.smiley.used_smiley_id.clear()
         slicer = MessageSlicerByTime()
         slices = slicer.slice(msgs)
 
diff --git a/lib/static/gen_smiley_css.py b/lib/static/gen_smiley_css.py
deleted file mode 100755
index 38789f2..0000000
--- a/lib/static/gen_smiley_css.py
+++ /dev/null
@@ -1,40 +0,0 @@
-#!/usr/bin/env python2
-# -*- coding: UTF-8 -*-
-# File: gen_smiley_css.py
-# Date: Wed Dec 24 22:20:08 2014 +0800
-# Author: Yuxin Wu <ppwwyyxxc@gmail.com>
-
-import os
-import glob
-import base64
-
-DIR_PATH = os.path.dirname(os.path.abspath(__file__))
-OUTPUT_FILE = os.path.join(DIR_PATH, 'smiley.css')
-
-HEAD = """.smiley {
-    padding: 1px;
-    background-position: -1px -1px;
-    background-repeat: no-repeat;
-    width: 20px;
-    height: 20px;
-    display: inline-block;
-    vertical-align: top;
-    zoom: 1;
-}
-"""
-
-TEMPLATE = """.smiley{name} {{
-    background-image: url("data:image/png;base64,{b64}");
-}}"""
-
-def get_file_b64(fname):
-    data = open(fname, 'rb').read()
-    return base64.b64encode(data)
-
-with open(OUTPUT_FILE, 'w') as f:
-    print >> f, HEAD
-    for fname in glob.glob(os.path.join(DIR_PATH, 'smileys', '*.png')):
-        b64 = get_file_b64(fname)
-        basename = os.path.basename(fname)
-        smileyname = basename[:-4]
-        print >> f, TEMPLATE.format(name=smileyname, b64=b64);